magento-test/app/code/Magento/Ui/view/base/templates/context/default.phtml

<?php
/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */
?>
<script data-mage-init='{ "Magento_Ui/js/core/app": "" }' type="application/json"></script>